Positraction Myth

[Joe L.]

Today an item closed on eBay (#2493525173) which was an original positraction plate kit of GM #9781862. This unit was used in PRODUCTION and SERVICE for 1965 through 1971 Corvettes. Beginning with the 1972 model year, the plate kit used in PRODUCTION and available in SERVICE was GM #483722 and that kit became the SERVICE kit for 65-71 models when the GM #9781862 was discontinued in December, 1971. The GM #483722 kit remained available in SERVICE until October, 1994 when it was replaced by kit GM #12524505. All of the kits, from first to last, were manufactured by Eaton.

Some folks think that the original kit, GM #9781862, is the superior one and that the 2 supercessive parts are inferior. Apparently, the person that won the above-referenced auction thinks so, too, since that person spent $374 for this old kit. The notion that the original kit is superior to the supercessive kits is a MYTH. The OPPOSITE is true. The GM #483722 kit was an IMPROVED KIT. You don't suppose that GM and Eaton went to the effort and expense of changing it because the original kit worked just as well, do you?

In any event, the GM #483722 will provide improved positraction clutch performance. I don't know how the current part, GM #12524505, compares, but my expectation is that it will provide improvement over the 483722. Regardless, I'm sure that it's at least as good.

The GM #12524505 currently GM lists for $105.22. So, why would anyone pay $374 for a functionally obsolete kit that no one will ever see once it's installed? Presumably, that's the power of the myth.

[Mark #28455]

Maybe they just like to collect NOS parts? *NM*

[Joe L.]

Re: Maybe they just like to collect NOS parts?

Mark-----

Perhaps. If so, though, they paid way too much. As a "curiousity piece" for a parts collection this piece would not be worth more than 50 bucks. Even that would be stretching it since the part would have little functional value.

[Craig S.]

Re: Maybe they just like to collect NOS parts?

Joe - the one caveat I would add is from Charley Smith's classes I took on rear end rebuilding. He used the successive kits for a period of time, but then dropped using the more recent GM kits in his rebuilds, and gets the current kits from Eaton directly or DTS. Basically, the more recent kits have slices radially in the some of the plates (I can't recall if it was the friction or steel plates). What he found, is that the way this desgin created "ears" in the plates, they were actually breaking off at times, which never happened on the original style or plates direct from Eaton but not through GM. He had rear ends coming back with problems, and dropped using them, and never had a problem since. He brought this up in a class at Bloomington several years back. I can't tell you which part numbers are which, but I believe I had a set of the last plates GM sold, and I sold them on eBay and assembled with the solid construction plates from Eaton instead based on his comments.....Craig